Electroplating apparatus

ABSTRACT

An exemplary electroplating apparatus includes an electroplating tank containing an electroplating solution and including a first side and a second side, a pay out reel arranged adjacent to the first side, a plurality of parallel anode plates in the electroplating solution, a plurality of first conveying rollers in the electroplating solution and adjacent to the first side of the electroplating tank, a plurality of second conveying rollers in the electroplating solution and adjacent to the second side of the electroplating tank, the conveying rollers arranged in a staggered fashion and aligned with the respective anode plates and being electrifiable to allow a current to flow through the flexible substrate, and a take up reel arranged adjacent to the second side. The conveying rollers cooperate to convey the flexible substrate from the pay out reel to the take up reel along a zigzag path.

BACKGROUND

1. Technical Field

The present disclosure relates to electroplating apparatuses and,particularly, to an electroplating apparatus for electroplating flexibleprinted circuit boards (FPCBs).

2. Description of Related Art

In recent years, FPCBs have been widely used in portable electronicdevices such as mobile phones, digital cameras, and personal digitalassistants (PDAs). In these portable electronic products, some parts maymove relative to a main body. In such applications, FPCBs can provideelectrical connections between the main body and the movable parts.

A conventional electroplating apparatus includes an electroplating tankcontaining electroplating solution, a conveying unit, two anode plates,and an electric brush. The conveying unit and the anode plates arelocated in the electroplating tank. A substrate to be electroplated ismoved along a straight line by the conveying unit. The anode plates areconfigured for supplying positive ions to the electroplating solution.The anode plates are located on two sides of the substrate, and areparallel with the movable direction of the substrate. In other words,the anode plates are perpendicular to the substrate.

The electric brush is configured to contact and supply electric currentto the substrate. Because the substrate moves along a straight line, theelectroplating tank must be very long. Accordingly, the electroplatingapparatus occupies a lot of space. In addition, the arrangement of theanode plates usually results in non-uniform densities of positive ionacross the substrate, which results in non-uniform thickness of the filmapplied to the substrate, thus a substrate with unsatisfactory qualityis achieved.

Therefore, it is desirable to provide a new electroplating apparatus,which can overcome the above mentioned limitations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an electroplating apparatus according toan exemplary embodiment.

FIG. 2 is a schematic view of the electroplating apparatus with aflexible substrate of FIG. 1.

DETAILED DESCRIPTION

Embodiments will now be described in detail below with reference todrawings.

Referring to FIG. 1, an electroplating apparatus 10 for electroplating aflexible substrate (not shown), in accordance with an exemplaryembodiment, is shown. The electroplating apparatus 10 includes amotorized pay out reel 11, a motorized take up reel 12, anelectroplating tank 13 containing an electroplating solution (notlabeled) and including a first side 132 and an opposite second side 133,a plurality of motorized first conveying rollers 140, 142, 144, and 146,a plurality of second conveying rollers 141, 143, and 145, a pluralityof motorized guide rollers (see below) that are insulated and configuredto guide the flexible substrate as detailed below, a motorized guideroller 16 that are electrifiable to allow a current to flow through theflexible substrate and configured to guide the flexible substrate asdetailed below, a plurality of anode plates 172-178, a plurality ofinsulated clapboards 180-187, a positive ion supply bath 19, and anautomatic positive ion supply system 20. The electroplating solution maybe a mixture of copper sulfate and sulfate.

The pay out reel 11 is arranged adjacent to the first side 132 of thetank 13 and is configured for paying out the flexible substrate into theelectroplating tank 13. The take up reel 12 is arranged adjacent to thesecond side 133 of the tank 13 and is configured for reeling in theelectroplated flexible substrate from the first and second conveyingrollers 140-146.

The electroplating tank 13 is circular in this embodiment, and includesa ring-shaped sidewall 130, and a bottom 131 perpendicular to thesidewall 130. In this embodiment, a mixing tube 134 is immersed in theelectroplating solution, and is arranged on the bottom 131. The mixingtube 134 is configured for producing gas bubbles to promote mixtureswirl in the electroplating solution.

The first conveying rollers 140, 142, 144, and 146 are immersed in theelectroplating solution in the tank 13 and adjacent to the first side132 of the tank 13. The first conveying rollers 140, 142, 144, and 146are electrifiable to allow a current to flow through the flexiblesubstrate, and are configured for revolving in a first rotatingdirection R1.

The second conveying rollers 141, 143, and 145 are immersed in theelectroplating solution and adjacent to the second side 133 of the tank13. The second conveying rollers 141, 143, and 145 are electrifiable toallow a current to flow through the flexible substrate, and areconfigured for revolving in a second rotating direction R2 opposite tothe first rotating direction R1.

The first and second conveying rollers 140-146 are arranged in astaggered fashion and aligned with the respective anode plates 172-178.The first and second conveying rollers 140-146 are configured forcooperating to convey the flexible substrate from the pay out reel 11 tothe take up reel 12 along a zigzag path 70 (see FIG. 2). The zigzag path70 includes a plurality of parallel zig segments 701 and a plurality ofparallel zag segments 703. The zig segments 701 parallel with the zagsegments 703. In the present embodiment, the zig segments 701 and zagsegments 703 are arranged in an alternate fashion and equidistantlyspaced.

In detail, the conveying rollers 140-146 are similar to each other andmechanically connected to a motor (not shown) by gears or belt (notshown), thereby making the conveying rollers 140-146 rotate together atthe same velocity. The conveying rollers 140-146 are made of stainlesssteel, and the surfaces of the conveying rollers 140-146 are coated withtitanium to prevent being electroplated. The first conveying rollers140, 142, 144, 146 are both vertically aligned and parallel with eachother as well as the bottom 131. The centers of the first conveyingrollers 140, 142, 144, and 146 are arranged in a straight line. Thedistance between the centers of each two adjacent first conveyingrollers of the first conveying rollers 140, 142, 144, and 146 is twotimes as long as the diameter of the first conveying roller 140.

The second conveying rollers 141, 143, and 145 are both verticallyaligned and parallel with each other as well as the bottom 131. Thecenters of the second conveying rollers 141, 143, and 145 are arrangedin a straight line. The distance between the centers of each twoadjacent conveying rollers of second conveying rollers 141, 143, and 145is two times as long as the diameter of the first conveying roller 140.

Along the depth direction of the tank 13, the distance between twocenters of each two adjacent conveying rollers of the first and secondconveying rollers 140-146 is equal to the diameter of the firstconveying roller 140. For example, along the depth direction of the tank13, the distance between two centers of the first conveying roller 140,and the second conveying roller 141 is equal to the diameter of thefirst conveying roller 140.

The motorized guide rollers, which are insulated and configured to guidethe flexible substrate, are immersed in the electroplating solution. Theguide rollers are similar to the conveying rollers, and the velocity ofrotation of each guide roller is equal to the velocity of rotation ofeach conveying roller. The guide rollers includes at least one firstguide roller 150, and at least one second guide roller 151. The at leastone first guide roller 150 is located between the pay out reel 11 andthe conveying rollers 140-146. The at least one first guide roller 150is configured for guiding the flexible substrate from the pay out reel11 to the conveying roller 140. The at least one second guide roller 151is located between the take up reel 12 and the conveying rollers140-146. The at least one second guide roller 15 is configured forguiding the electroplated flexible substrate from the conveying roller146 to the take up reel 12. In the present embodiment, there is onefirst guide roller 150, and there are two second guide rollers 151. Thefirst guide roller 150 is arranged at the first side 132 and near thefirst conveying roller 140, and a gap (not shown) is preserved betweenthe first guide roller 150 and the first conveying roller 140. Thesecond guide rollers 151, which is arranged at the second side 133 andnear the second conveying roller 140, and the first conveying roller 140are arranged at the same depth, and a gap (not shown) is preservedbetween the second guide rollers 151.

The motorized guide roller 16, is located at the second side 133, and isarranged between the second guide rollers 151 and the conveying rollers140-146. In the present embodiment, the guide roller 16 and theconveying roller 146 are arranged at the same depth, and the guideroller 16 is nearer to the sidewall 130 than the second conveyingrollers 141, 143, and 145.

The anode plates 172-178 are immersed in the electroplating solution,and are parallel with each other. The anode plates 172-178 areconfigured to electroplate the flexible substrate. In the presentembodiment, the anode plates 172-178 are equidistantly spaced insolubleanodes, and are oriented parallel to a surface of the electroplatingsolution.

Each of the anode plates 172-178 includes a first end 170, and anopposite second end 171. In each two adjacent anode plates, the twofirst ends 170 of the two adjacent anode plates are adjacent to eachother, and the two second ends 171 of the adjacent two anode plates areadjacent to each other. The first end 170 of one anode plate in the twoadjacent anode plates is adjacent to one first conveying roller, and thesecond end 171 of the other anode plate in the two adjacent anode platesis adjacent to one second conveying roller, thereby making the flexiblesubstrate move between the two adjacent anode plates when the flexiblesubstrate is threaded around the two conveying rollers. In the presentembodiment, the anode plates 172-178 are copper plates coated withtitanium; the first ends 170 are located adjacent to the first side 132of the tank 13 as the pay out reel 11, and the second ends 171 arelocated adjacent to the second side 133 of the tank 13 as the take upreel 12. The distance between each two adjacent anode plates is equal tothe diameter of the first conveying roller 140, and the center ofconveying roller and the corresponding anode plate is in a straightline.

In detail, the first end 170 of the anode plate 172 is adjacent to thefirst conveying roller 140, and the first end 170 of the anode plate 172and the center of the first conveying roller 140 are in a straight line.The second end 171 of the anode plate 172 aligns with the edge of thesecond conveying roller 141. The second end 171 of the anode plate 173is adjacent to the second conveying roller 141, and the second end 171of the anode plate 173 and the center of the second conveying roller 141are in a straight line. The second end 170 of the anode plate 173 alignswith the first conveying roller 140. The arrangements of the anode plate174, the anode plate 176, and the anode plate 178 are similar to that ofthe anode plate 172, expect that the second end 171 of the anode plate178 is adjacent to the guide roller 16, and the second end 171 of theanode plate 178 and the centers of the guide roller 16 are in a straightline. The arrangements of the anode plate 175, the anode plate 177 aresimilar to that of the anode plate 173.

The insulated clapboards 180-187 are immersed in the electroplatingsolution, and are connected with the respective anode plates forseparating the anode plates 172-178 from the corresponding first andsecond conveying rollers 140-146.

In detail, the insulated clapboard 180 is located between the firstconveying roller 140 and the first end 170 of the anode plate 172, andis connected with the first end 170 of the anode plate 172. Theinsulated clapboard 181 is located between the conveying roller 141 andthe second end 171 of the anode plate 173, and is connected with thesecond end 171 of the anode plate 173. The insulated clapboard 182 islocated between the conveying roller 142 and the first end 170 of theanode plate 174, and is connected with the first end 170 of the anodeplate 174. The insulated clapboard 183 is located between the conveyingroller 143 and the second end 171 of the anode plate 175, and isconnected with the second end 171 of the anode plate 175. The insulatedclapboard 184 is located between the conveying roller 144 and the firstend 170 of the anode plate 176, is connected with the first end 170 ofthe anode plate 176. The insulated clapboard 185 is located between theconveying roller 145 and the second end 171 of the anode plate 177, andis connected with the second end 171 of the anode plate 177. Theinsulated clapboard 186 is located between the conveying roller 146 andthe first end 170 of the anode plate 178, and is connected with thefirst end 170 of the anode plate 178. The insulated clapboard 187 islocated between the guide roller 16 and the second end 171 of the anodeplate 178, and is connected with the second end 171 of the anode plate178.

In this embodiment, each of the insulated clapboards 180-187 isperpendicular to the corresponding anode plates 172-178, and the lengthof each insulated clapboard along a direction perpendicular to thecorresponding anode plate is longer than the thickness of thecorresponding anode plate. In the present embodiment, the insulatedclapboards 180-187 are square plates, and are made of acrylonitrilebutadiene styrene. In other embodiment, the insulated clapboards 180-187may be made of polyvinylchloride.

In alternative embodiments, the number of the conveying rollers is notlimited to seven; the number of the anode plates is not limited toseven; the number of the insulated clapboards is not limited to eight.In further alternative embodiments, the anode plates 172-178 may beperpendicular to the bottom 131. In other further alternativeembodiments, the anode plates 172-178 may be inclined relative to thecentral axis of the tank 13.

The positive ion supply bath 19 is configured for supplying a positiveion solution to the tank 13. The positive ion supply bath 19 includes adelivery pipe 190. In the present embodiment, the positive ion solutionis sulfate for dissolving copper sulfate to obtain positive copper ions.

The automatic positive ion supply system 20 includes a positive ionconcentration detector 21, a controlling device 22, and an infusion pump23. The concentration detector 21 is immersed in the electroplatingsolution for detecting the positive ion concentration in theelectroplating solution in the tank 13. The infusion pump 23 isconnected to the positive ion supply bath 19 by delivery pipe 190. Thecontrolling device 22 is configured for receiving detected positive ionconcentration values from the concentration detector 21, and controllingthe infusion pump 23 to pump the solution in the positive ion supplybath 19 into the tank 13 when the detected positive ion concentrationvalue is lower than a predetermined value.

Referring also to FIG. 2, a usage method of the electroplating apparatus10 will be described below.

First of all, a flexible substrate 100 is provided. The flexiblesubstrate 100 can be a soft substrate with the two opposite surfacescoated with copper layers formed by chemical deposition. Most of theflexible substrate 100 is wound onto the pay out reel 11, and some ofthe flexible substrate 100 is set between the conveying rollers, and theguide rollers. In detail, one end of the flexible substrate 100 ispassed through the gap between the first guide roller 150 and theconveying roller 140, and then is threaded around the conveying roller141, the conveying roller 142, the conveying roller 143, the conveyingroller 144, the conveying roller 145, the conveying roller 146, and theguide roller 16 in that order, and finally passes through the gapbetween the second guide rollers 151 and to be wound onto the take upreel 12.

Then, an electric source (not shown) of the electroplating apparatus 10is turned on, and the flexible substrate 100 is reeled through the tank13 and electroplated.

The electroplating process for a section of the flexible substrate 100,which is about to enter into the tank 13, will be described below.

As can be clearly seen in FIG. 2, the section of the flexible substrate100 reeled through the tank 13 can be conveyed and guided by the rollersin order from the first guide roller 150, the conveying rollers 140-146,the guide roller 16 then through the gap between the guide rollers 15,and wound onto the take up reel 12. During the trip through the tank 13,due to electric current in the copper layers on the flexible substrate100 supplied by the rollers 140-146 and the guide roller 16, the copperion in the electroplating solution will generate a chemical reaction toobtain Cu. The obtained Cu is gradually deposited on the surface of theflexible substrate 100.

In the electroplating process, because each anode plate is parallel thesurface of the flexible substrate 100, and distances between differentpoints at the surface of the flexible substrate 100 and thecorresponding anode plates are equal to each other, the positive iondensities at the different points are equal to each other on the surfaceof the flexible substrate 100, thereby making the electroplating layerformed on the surface of the flexible substrate 100 have a satisfactoryuniform thickness. In addition, the conveying rollers in theelectroplating apparatus 10 not only supply current to the flexiblesubstrate 100, but also move the flexible substrate 100, and convert themovable direction of the flexible substrate 100, thereby making theflexible substrate 100 move back and forth regularly. Accordingly, thelength of the tank 13 can thus be reduced, and the electroplatingefficiency can be improved.

While certain embodiments have been described and exemplified above,various other embodiments will be apparent to those skilled in the artfrom the foregoing disclosure. The disclosure is not limited to theparticular embodiments described and exemplified but is capable ofconsiderable variation and modification without departure from the scopeand spirit of the appended claims.

1. An electroplating apparatus for electroplating a flexible substrate,comprising: an electroplating tank containing an electroplatingsolution, the electroplating tank including a first side and an opposingsecond side; a pay out reel arranged adjacent to the first side of theelectroplating tank and configured for paying out the flexiblesubstrate; a plurality of parallel anode plates immersed in theelectroplating solution and configured to electroplate the flexiblesubstrate; a plurality of first conveying rollers immersed in theelectroplating solution and adjacent to the first side of theelectroplating tank; a plurality of second conveying rollers immersed inthe electroplating solution and adjacent to the second side of theelectroplating tank, the first and second conveying rollers arranged ina staggered fashion and aligned with the respective anode plates, thefirst and second conveying rollers being electrifiable to allow acurrent to flow through the flexible substrate, and a take up reelarranged adjacent to the second side, the first and second conveyingrollers configured for cooperating to convey the flexible substrate fromthe pay out reel to the take up reel along a zigzag path, the take upreel configured for reeling in the flexible substrate from the conveyingrollers.
 2. The electroplating apparatus of claim 1, wherein the anodeplates are equidistantly spaced.
 3. The electroplating apparatus ofclaim 1, wherein the first conveying rollers are configured forrevolving in a first rotating direction, and the second conveyingrollers are configured for revolving in a second rotating directionopposite to the first rotating direction.
 4. The electroplatingapparatus of claim 1, wherein the zigzag path includes a plurality ofparallel zig segments and a plurality of parallel zag segments, the zigsegments parallel with the zag segments.
 5. The electroplating apparatusof claim 4, wherein the zig segments and zag segments are arranged in analternate fashion and equidistantly spaced.
 6. The electroplatingapparatus of claim 1, further comprising a plurality of insulatedclapboards connected with the respective anode plates for separatinganode plates from the corresponding first and second conveying rollers.7. The electroplating apparatus of claim 6, wherein each of the insulateclapboard is perpendicular to the corresponding anode plate.
 8. Theelectroplating apparatus of claim 7, wherein the length of each theinsulated clapboard along a direction perpendicular to the correspondinganode plate is longer than the thickness of the corresponding anodeplate.
 9. The electroplating apparatus of claim 1, further comprising apositive ion supply bath for supplying a positive ion solution to theelectroplating tank, wherein the anode plates are insoluble anodes. 10.The electroplating apparatus of claim 9, further comprising an automaticpositive ion supply system, the automatic positive ion supply systemcomprising a positive ion concentration detector, a controlling device,and an infusion pump, the concentration detector being immersed in theelectroplating solution for detecting the positive ion concentration inthe electroplating solution, the infusion pump being connected to thepositive ion supply bath, the controlling device being configured forreceiving detected positive ion concentration value from theconcentration detector, and controlling the infusion pump to pump thesolution in the positive ion supply bath into the electroplating tankwhen the detected positive ion concentration value is lower than apredetermined value.
 11. The electroplating apparatus of claim 1,further comprising a mixing tube immersed in the electroplatingsolution, the mixing tube being configured for producing gas bubbles topromote mixture swirl in the electroplating solution.
 12. Anelectroplating apparatus for electroplating a flexible substrate,comprising: an electroplating tank containing an electroplatingsolution, the electroplating tank including a first side and an opposingsecond side; a pay out reel arranged adjacent to the first side of theelectroplating tank and configured for paying out the flexiblesubstrate; a plurality of parallel anode plates immersed in theelectroplating solution and configured to electroplate the flexiblesubstrate; a plurality of first conveying rollers immersed in theelectroplating solution and adjacent to the first side of theelectroplating tank; a plurality of second conveying rollers immersed inthe electroplating solution and adjacent to the second side of theelectroplating tank, the first and second conveying rollers arranged ina staggered fashion and aligned with the respective anode plates, thefirst and second conveying rollers being electrifiable to allow acurrent to flow through the flexible substrate; a take up reel arrangedadjacent to the second side, the first and second conveying rollersconfigured for cooperating to convey the flexible substrate from the payout reel to the take up reel along a zigzag path, the take up reelconfigured for reeling in the flexible substrate from the conveyingrollers, and a mixing tube immersed in the electroplating solution, themixing tube being configured for producing gas bubbles to promotemixture swirl in the electroplating solution.
 13. The electroplatingapparatus of claim 12, wherein the anode plates are equidistantlyspaced.
 14. The electroplating apparatus of claim 12, wherein the firstconveying rollers are configured for revolving in a first rotatingdirection, and the second conveying rollers are configured for revolvingin a second rotating direction opposite to the first rotating direction.15. The electroplating apparatus of claim 12, wherein the zigzag pathincludes a plurality of parallel zig segments and a plurality ofparallel zag segments, the zig segments parallel with the zag segments.16. The electroplating apparatus of claim 15, wherein the zig segmentsand zag segments are arranged in an alternate fashion and equidistantlyspaced.
 17. The electroplating apparatus of claim 12, further comprisinga plurality of insulated clapboards connected with the respective anodeplates for separating anode plates from the corresponding first andsecond conveying rollers.
 18. The electroplating apparatus of claim 17,wherein each of the insulate clapboard is perpendicular to thecorresponding anode plate.
 19. The electroplating apparatus of claim 12,further comprising a positive ion supply bath for supplying a positiveion solution to the electroplating tank, wherein the anode plates areinsoluble anodes.
 20. The electroplating apparatus of claim 12, whereinthe anode plates are oriented parallel to a surface of theelectroplating solution.